Model Engine Maker
Help! => Hints, Tips & Tricks => Topic started by: cfellows on October 19, 2017, 08:42:32 PM
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This is a 3mm setscrew that I was trying to remove with a 1.5mm allen wrench.
(https://i.imgur.com/Hj9qyDw.jpg?1)
It was locked up so tight I knew I would twist off the allen wrench before the screw let loose. I put some liquid wrench on it and left it for around 18 hours or so, but it was still stuck tight. I couldn't use heat because of the proximity of plastic that part was attached to. So, using the allen wrench, I started going back and forth, tightening and loosening as far as I dared go, even thought he screw wasn't moving, at first. Eventually, the screw started to move and each back and forth made it loosen more and more. Finally, I got it to come out. Turns out, threadlock of some kind had been used and that was what I was fighting against. I wonder if the same technique would work on rusted or corroded screws that are stuck?
Chuck
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We have some stuff over here called shock and un-lock - that might have helped. But I have used the repeated tighten / loosen technique on rusted fasteners before.
Simon.
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Yes. I have done it for years. With each little advance I spray more penetrating oil. It is a game of patience; especially when removing spark plugs with 100K miles on them.
-Bob
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Glad you prevailed Chuck. I will file that away for future reference.
Bill
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That's the only way I've found to work if you can't use the blue wrench. Tap and wiggle and lots of penetrating fluid.
I've found that sometimes lacquer thinner penetrates these small parts better than Kroil. But once there is some movement then fluids with some oil come to play nicely.
That's a small screw!
Pete
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I work on old Girling shock absorbers and one of the tricks I've learned is using two ball peen hammers. One to hit the other which is placed on the shock the lid, it seems to break the lid free from the rust. Then using an impact wrench to break it loose. Mind you these are 1 1/4 to 1 3/8 diameter threads about 1/4 inch thick. Popping it a couple times with a hammer seems to do the trick.
Art
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sometimes, with a screw such as the one in the photo, that I can't get to turn, a small punch down in the socket, and a firm hit with a hammer is enough to alow some movement, then wiggle back and forth, and it comes out. if the hex is rounded/or I don't have a key to fit, cut a screw driver slot with a thin dremmel grinding wheel
ian S C
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On some larger stuff the hand held impact driver frequently works well. It gives a shock and a slight twist at each blow.
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You only need to heat the grub screw: put a piece of hex in the hole and heat the end of the hex... the heat goes down its length and kills the Loctite. Just do it carefully, you only need to slightly heat the screw from the heat transfer, not the rest of the item.
Jo
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Along the lines of what Jo says. When a flame isn't practical a soldering iron can be effective.
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... using two ball peen hammers. One to hit the other ...
Art, I hope you wear gauntlets and full face protection when hitting one hammer with another. They are both hardened and therefore somewhat brittle and you can get steel splinters flying off. I've not seen it happen, but I have seen the result.
Far safer to use one hammer to hit a suitable sized drift of unhardened metal.
George
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If your part really can't be heated, try soaking in MEK or acetone overnight. Both will soften the acrylic resin used in loctite. Of course, that assumes your plastic part isn't also made from acrylic (Delrin/acetal plastic by the way, is resistant to acetone and MEK).
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Thanks for all the comments and suggestions, guys. Unfortunately, I didn't know that Loctite was in play here. I figured it might just be rusted or corroded...
Chuck
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I’d go with a small Allen key stud and hit with hammer. If can get open ended ratchet ring on the stud then turning it at same time gives same effect as a impact wrench. Use the same trick with wood screws. Turn screwdriver at same time as hit with mallet/hammer. Tightening it frst usually helps.
Colin